Tufting needle and method of making same



Dec. 5, 1967 J. T. SHORT Y 3,356,047

- TUFTING NEEDLE AND METHOD OF MAKING SAME Filed Aug. 2, 1965 YARN FEED 29 I 2 J2 MECHANISM I 2 26 v 3* iiyj *- 28 Joe T5501? ATTORNEYS United States Patent Ofiice 3,356,047 Patented Dec. 5, 1967 3,356,047 TUFTING NEEDLE AND METHOD OF MAKING SAME Joe T. Short, West Point, Ga, assignor to Callaway Mills Company, La Grange, Ga., a corporation of Georgia Filed Aug. 2, 1965, Ser. No. 476,407 6 Claims. (Cl. 11279) This invention is a continuation-in-part of my copending application, Ser. No. 267,076, filed Mar. 22, 1963 and entitled, Tufting Apparatus, now Patent No. 3,217,676.

This invention relates to a means and method of tufting and is more particularly concerned with a hollow tufting needle, a method of tufting and a method of producing the tufting needle.

In the past, hollow tufting needles have been utilized in both multi-needle tufting machines and in mending guns. These prior art tufting needles have included tubular shanks in which the tufting ends were formed by cutting the cylindrical tubular needle ends at an angle to the axis of the needle. This, however, provided a tufting needle which tended to sever the yarn and, if a large diameter needle were used, tended to sever the backing material, or at least the filling yarns of the backing material, when a large number of stitches per inch were sewn.

Such prior art needles which have beveled tufting ends tended to urge only one filling yarn out of position in creating a hole in a backing material. Therefore, when a plurality of such needles were disposed transversely of the backing material and closely adjacent each other, as in a multi-needle tufting machine, these needles simultaneously displaced many increments of asingle filling yarn in a backing material, thereby tending to stretch the filling yarn beyond its elastic limits. Hence, in many instances, the filling yarn, after passing beyond the tufting zone, was broken in one or several places or was in such a weakened condition that when the carpeting was subjected to heat and moisture or stretched for laying as wall-to-wall carpeting, it tended to split or disintegrate.

When tufting jute (or other comparable backing material) with a high number of stitches per inch, there is only one or two filling yarns of such jute between adjacent tufts in a longitudinal row of tufts. Therefore, if a filling yarn in the jute (or other comparable backing material )is severed by the tufting needle, there is a likelihood that such severing is manifest by the creation of a single loop of yarn from two adjacent loops, the single loop of yarn being approximately twice the height of either of the intended two loops.

While the prior art has suggested a hollow tufting needle having a solid point and a yarn passageway terminating on one side of the needle above the solid point, such a tufting needle cannot be manufactured readily or inexpensively. Furthermore, it is probable that such a needle will not function as well as a needle having a straight yarn passageway, especially is this true if such a needle is to be used in a multi-needle tufting machine in which the yarns are discharged beyond the extent of penetration of needles through the backing material. In-

deed, there has been no suggestion that such needles could be used in this way.

Briefly described, the present invention, which tends to obviate the problems described above, includes a hollow cylindrical tufting needle of the type having a yarn passageway which will permit the discharge of the yarn along the axis of the needle and in which the yarn discharge end of the needle is swaged inwardly to provide camming surfaces for urging apart both of the filling yarns in a backing material (rather than only one filling yarn) as the needle creates a hole. The needle of the present invention also has camming surfaces to act on the warp yarns of the backing material as the needle penetrates the backing material. The camming surfaces are substantially harder than the shank of the needle so that the needle, while being resistant to shock and flexure, due to the less hard shank, is also resistant to abrasion in the region where the major portion of the abrasion occurs.

The needle of the present invention also has rounded surfaces along the rear and side edges of the yarn discharge end so as to reduce the likelihood that the needle will sever the yarn.

The present invention also contemplates a new and novel method of forming the needle yarn discharge end through the use of a particularly shaped swage block and the movement of the needle into and out of the swage block.

Accordingly, it is an object of the present invention to provide a tufting needle which will more quickly and easily function to insert yarn through a backing material.

Another object of the present invention is to provide a tufting needle from which yarn may be discharged by air essentially unimpeded by the configuration of the needle and which is capable of operating at a high speed with a minimum of friction with respect to the backing material being tufted.

Another object of the present invention is to provide a hollow tufting needle which will reduce the force required to insert the same through a backing.

Another object of the present invention is to provide a tufting needle which is capable of urging the warp and filling yarns more uniformly apart for creating a hole in a backing material to receive the yarn carried by the needle.

Another object of the present invention is to provide a hollow tufting needle which will receive and tuft larger diameter yarns than heretofore believed suitable for use in such hollow needles.

Another object of the present invention is to provide a hollow tufting needle which is capable of displacing simultaneously both filling yarns in creating a hole for receiving a tuft in a backing material.

Another object of the present invention is to provide a hollow tufting needle which will sew tufts more closely than conventional hollow tufting needles.

Another object of the present invention is to provide a hollow tufting needle which, while being resistant to shock, nevertheless will withstand wear resulting from repeated insertion of the needle through a backing material.

Another'object of the present invention is to provide a hollow tufting needle which is inexpensive to manufacture, durable in structure and efficient in operation.

Another object of the present invention is to provide an improved method of tufting yarn into a backing material. 7

Another object of the present invention is to provide a quick'and easy method of manufacture of the improved hollow needle of the present invention.

Other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views and wherein:

FIG. 1 is a fragmentary, vertical sectional view of a needle bar having mounted therein hollow tufting needles constructed in accordance with the present invention and showing, schematically, a yarn feed mechanism feeding yarns to the needles and the needles operating to sew loops of yarn in a backing material;

FIG. 2 is an enlarged horizontal sectional view taken substantially along line 2-2 in FIG. 1;

FIG. 3 is an enlarged, fragmentary vertical sectional view from one side of the yarn discharge end of the needle shown in FIG. 1;

FIG. 4 is an enlarged, rear elevational view of that portion of the needle illustrated in FIG. 3;

FIG. 5 is a fragmentary vertical sectional view of a swage block receiving the yarn discharge end of a needle for swaging action according to the present invention.

Referring now in detail to the embodiment chosen for the purpose of illustrating the present invention, it being understood that, in its broader aspects, the present invention is not limited to the exact details herein depicted, numeral in FIG. 1 denotes a hollow needle bar closed on all sides for defining a chamber 11 to which fluid under pressure, such as compressed air, is fed from a flexible hose (not shown) connected to a pipe 12 extending through the back wall 13 of the needle bar 10. The needle bar 10 includes an upper plate 14 and a lower plate 15 disposed parallel to each other and extending the length of the needle bar 10. The needle bar 10 also includes a front plate 16 which is bolted by bolts 17 to the front edges of plates 14 and 15, the front plate 16 being spaced downwardly with respect to the upper surface of plate 14 and having a gasket 18.

The upper plate 14 and the lower plate 15 are respectively provided with a plurality of staggered holes forming two rows of holes substantially throughout their length, the axes of the holes in upper plate 14 being respectively aligned vertically with the axes of the holes in the lower plate 15. If desired, only a single row or three or more rows of such holes may be provided. The arrangement of needles on a needle bar, however, is well known in the art and therefore no detail discussion of such arrangement is deemed necessary.

Each pair of aligned holes in the upper plate 14 and lower plate 15 receives a needle, denoted generally by the numeral 20. Each needle 20 includes, as seen in FIG. 1, a body 21 and a shank 22 having a yarn discharge end 23. The body 21 and the shank 22, except for the discharge end 23, are identical in construction to the construction of the needle illustrated in my co-pending application, Ser. No. 267,076, now Patent No. 3,217,676, and, therefore, no detailed description of this hollow needle 10 is deemed necessary, except to state that the body 21 is received in the holes in upper plate 14 and lower plate 15 and has 0 rings 19 to prevent the passage of fluid from the chamber 11 through the holes in plates 14 and 15. The body 21 is bored throughout in length to provide a straight yarn passageway 24 disposed along its axis. In the central portion of body 21 are a plurality of radially spaced fluid passageways 25 which converge downwardly in the direction of discharge of the yarn 26 from the body 21. The fluid passageways 25 communicate at their upper or outer ends with the chamber 11 of the needle bar 10 and communicate at their lower or inner ends with the yarn passageway 24 so that fluid from the chamber 11 may be introduced into the yarn passageway 24 for urging the yarn 26 out of the passageway 24.

The lower end of the body 21 is counterbored to a slightly larger diameter than the diameter of the yarn passageway 24 for receiving the inlet end of shank 22. At the mouth of the yarn passageway 24, the body 21 is chamfered to provide an inwardly and downwardly tapered yarn entrance or inlet 27.

It will be understood that, in the multi-needle tufting machine, a plurality of yarns 26, are fed from a creel (not shown) to a yarn control or yarn feed mechanism 29 and thence along essentially parallel downwardly inclined paths to the respective needles 20. Each yarn 26 passes into the yarn entrance 27 of its associated needle 20, and thence, down through the yarn passageway 24 to the yarn passageway 28. From the yarn passageway 28, the yarn 26 is fed out of the yarn discharge end 23.

The tips 35 of the yarn discharge ends 23 of all needles 2t) terminate in essentially a single plane parallel to needle bar 10 and a backing material 31 is disposed beneath the plane of the tips 35. The backing material 31 is fed along a predetermined path, from right to left in FIG. 1, and the needle bar 10 is reciprocated in a vertical path through a small amplitude sufiicient to insert the yarn discharge ends 23 through the backing material 31 so as to expose it to the face side of the backing material 31 and then withdraw it from the backing material 31.

The backing material 31 is preferably woven jute having warp yarns 32 and filling yarns 33. Other backing materials, both woven and unwoven, may suggest themselves to those skilled in the art; however, regardless of the type of such backing material, the needle 20 of the present invention should retain its advantages over conventional needles, as hereinafter pointed out in respect to the preferred backing material 31.

The apparatus and process thus far described has been disclosed in my co-pending application, Ser. No. 267,076.

According to the present invention, the yarn discharge end 23 is first cut at an angle to the axis of shank 22, then rough ground to provide the rounded edges, next subjected to swaging action, then to another grinding and polishing operation and finally heat treated.

In more detail, the needle 20 is preferably produced using a yellow brass screw machine stock for body 21 and carbon steel tubing for the shank 22. The body 21 is produced from brass so that it may be readily machined to the shape illustrated in FIG. 1 and will absorb shock transmitted through the needle shank 22 thereto.

On the other hand, the shank should be harder, having a spring temper. It will be understood by those skilled in the art that it is diflicult to measure the hardness of a piece of thin tubular steel, due to the fact that it tends to flex during testing, however, the measurements indicate that the preferred hardness of the shank 22 should be between 43 and 47 Rockwell C.

The yarn discharge end 23 is produced by cutting in a straight cut, the end portion of shank 22, the angle of the cut being at approximately 30 degrees to the axis of shank 22. Hence, the discharge end 23 has a discharge opening which is oval or elliptical in shape. Since the sharp edged mouth 34 of the discharge end 23 would tend to sever the yarn 26, the mouth 34 is rounded. This is accomplished by a grinding operation in which the edge or mouth 34, rearwardly of tip 35, is provided with a rtunded shape, particularly at its rear or upper extremity 3 Next, the discharge end 23 is subjected to a swaging operation. This swaging operation urges the metal, forming the discharge end 23, inwardly toward the axis of shank 22 to provide camming surfaces which more readily open the adjacent warp yarns 32 and filling yarns 33 as the needle 20 penetrates backing material 31. For readily and easily creating the camming surfaces, a swage block 40 is produced by boring a block of metal to provide a cylindrical guide hole 41 communicating with a base end of a tapered or conical swage hole 42. The hole 41 is a straight cylindrical hole leading from the outside surface of block 40 inwardly and is of substantially less length than the length of shank 22. Guide hole 41 is of a diameter approximately .002 inch larger than the outside diameter of shank 22. Therefore, when shank 22 is inserted, discharge end first, into hole 41, the guide hole 41 maintains a coaxial relationship between shank 22 and swage hole 42.

The swage hole 42 subtends an angle of approximately 12 degrees between opposed walls defining the hole and has a base equal in diameter to the diameter of hole 41. In producing the swaged discharge end 23, the shank 22 is inserted through the hole 41 to a predetermined distance which is preferably only sufiicient for the discharge end 23 to enter hole 42, i.e., to a point where the upper extremity 36 of the mouth 34 is at the base of hole 42. This, of course, causes the tip 35 to be displaced inwardly, .to a greater extent than the opposed camming sides 37 and 38 of discharge end 23. The shank 22 is then with drawn.

It is now seen that the discharge end 23 is provided with a taper in which the front camming surface, denoted by numeral 39, is perceptably deformed inwardly, the contour of surface 39 being convex from tip 35 to a point diametrically opposed to upper extremity 36, where it merges with the outer surface of shank 22, as seen in FIG. 3. From tip 35 to upper extremity 36, the mouth 34 is progressively less deformed, the opposed camming sides 37 and 38 being deformed inwardly by the same amount.

The working and rearranging of the metal, as described above, may cause a bulge to develop in the region of upper extremity 36 and, if this occurs, it will not materially detract from the operation of the needle 20.

In the next operation of manufacture, the final transverse curvilinear convex cross-sectional shape is imparted to the wall of mouth 34, rearwardly of tip 35, by further grinding and polishing the same so that no burrs or ragged increments of mouth 34 exist.

Finally, from approximately th inch to approximately firth inch of the discharge end 23 is hardened by subjecting the same to a temperature of approximately 1600 degrees F. and then quenching it in oil. This creates a hardened ring 45, shown by the stippled area of the drawings, which is of a hardness of from approximately 62 to approximately 65 Rockwell C. Thereafter, the discharge end 23 is again polished.

It will now be seen that the discharge end 23 is quite hard and brittle while the shank 22 remains tough and somewhat flexible.

Operations From the foregoing description, it will be seen that, in operation, the needle bar 10, seen in FIG. 1, is reciprocated up and down through a sufiicient amplitude to remove the tip 35 from the backing material 31 and then insert the yarn discharge end 23 through the backing material 31 to an extent only to expose the yarn discharge end 23 to the face side of the backing material 31. This reciprocation is in conjunction with the movement of the backing material 31 from right to left in FIG. 1. At the same time, yarn 26 is fed from the yarn feed mechanism 29, varying rates according to a predetermined pattern, to the needles 20 as compressed air or some other fluid under pressure is introduced through pipe 12 to the chamber 11 and thence through the air passageways 25 to the yarn passageway 24 for urging the yarn 26 out of the needle in a downwardly direction, to the extent permitted by the yarn feed mechanism 29. This simultaneous operation of the compressed air, the needle bar the yarn feed mechanism 29 and the feeding of the backing material 31 enables each needle 20 to create a longitudinal row of successive loops 46 in the backing material 31. In normal operation, the loops 46 are urged by the air emerging from the yarn discharge end 23, beyond the extent of penetration of the tip 35 through the backing material 31.

As each needle 20 is carried downwardly by the needle bar 10, the tip 35 first penetrates the backing material 31 and orients itself between an adjacent pair of filling yarns 33 and an adjacent pair of warp yarns 32 so as to progressively urge the filling yarns 33 apart and the warp yarns 32 apart, the camming surface 39 acting upon the trailing filling yarn 33, and the camming surface created by the beveled mouth 34 acting upon the leading filling yarn 33. At the same time, the swaged or inwardly tapered sides 37 and 38 tend to urge the warp yarns 32 apart.

Since the tip portion or yarn discharge end 32 is quite hard, as explained above, the abrasion due to repeated insertion of the yarn discharge end 23 through the backing material 31 does not readily wear away the yarn discharge end to any appreciable extent. Indeed, an unswaged and unhardened hollow tufting needle may be expected to have a life suflicient to sew from approximately 15,000 to approximately 20 ,000 linear yards of backing material 31 whereas a tufting needle constructed in accordance with the present invention will have a useful life in excess of 375,000 linear yards of backing material 31.

It is also quite significant to note that if a tufting needle is produced in accordance with the present invention, a shank having an outside diameter of .145 inch may be used in a 5/32 gauge tufting machine to produce seven stitches per inch in a ten-ounce jute whereas, heretofore, a needle having a shank diameter of .135 inch was about the largest needle which could reasonably be used in such a machine on a ten ounce jute to produce seven stitches per inch. I have also'found that, utilizing a .135 outside diameter shank produced according to the present invention, 7 /2 stitches per inch of tufting can be produced without damaging the backing material, 'as opposed to seven stitches per inch utilizing an unhardened and un- -swaged tufting needle of the same diameter. Furthermore,

by enabling the use of a .145 diameter shank, as opposed to a .135 diameter shank, the size of the tufting yarn utilized in the hollow needle of the present invention can be increased beyond the 3700 denier continuous filament yarn which was heretofore believed to be the practical limit of the yarn size. Furthermore, while it has heretofore been believed impractical to sew, with a hollow tufting needle, spun yarns having a size greater than about 2/2 ply cotton count, utilizing a needle produced according to the present invention, the yarn size can be increased to 2.87/3 ply cotton count for producing 6 stitches per inch, provided the .145 inch diameter shank were used.

It is also significant that, by utilizing a needle produced in accordance with the present invention, the horsepower requirement of a hollow needle tufting machine may be appreciably reduced, due to the decrease in force required for penetrating the backing material with the needles.

As pointed out above, the tufting needle produced in accordance with the present invention operates quite satisfactorily on non-woven backing material in that it tends to shift the fiber-s forwardly and rearwardly, as well as to the sides in creating a hole therein, in much the same manner as the tufting needle of the present invention shifts the filling yarn 33 forwardly and rearwardly, as illustrated in FIG. 2.

It will be obvious to those skilled in the art that many variations may be made in the embodiments here chosen or the purpose of illustrating the present invention, without departing from the scope thereof as defined by the appended claims.

I claim:

1. A tufting needle comprising a cylindrical shank provided with a cylindrical axial yarn passageway, and

means to admit air to said passageway to blow yarn therethrough,

said shank being beveled at its lower end, said passageway having a yarn inlet opening at one end and an inclined elliptical yarn discharge opening at its other end defined by the beveled lower end of said shank, said elliptical yarn discharge opening being in axial alignment with said passageway, said beveled lower end of said shank being arcuate in cross section and having a taper extending convexly inwardly substantially around its entire circumference, said taper merging smoothly with the remainder of said shank at a circumferential line around said shank near the upper periphery of said elliptical opening so that the length of the taper is greatest on the side of the shank which defines the lower periphery of said elliptical opening and progressively decreases around the shank in both directions from said side,

whereby the lower end of said needle provides a camming surface substantially surrounding an elliptical outlet through which the yarn may be air blown in an axial direction without binding the yarn.

2. A tufting needle as recited in claim 1 wherein a portion of said shank surrounding said discharge opening is harder than the remaining portion of said shank.

3. A tufting needle as recited in claim 1 wherein said shank has a downwardly directed elliptical lower edge defining a rim around said elliptical opening,

said lower edge having an upper portion with a rounded cross section at the top of said elliptical opening, a relatively sharper lower portion at the bottom of said elliptical opening, and

side portions extending between and gradually merging with said rounded upper portion and said sharper lower portion.

4. A tufting needle as recited in claim 3 wherein a bottom portion of said shank around said rim is harder than the remaining portion of said shank.

5. A method of producing the shank of a tufting needle comprising the steps of cutting an end portion of a hollow cylindrical tube along a bevel with the axis of said tube to form an elliptical opening with its lower periphery at the lower end of the bevel,

pressing said end portion into a converging conical opening in a swage block to shape the exterior surface of said end portion into a convex, inwardly tapered camming surface, continuing said pressing until the taper extends to a circumferential line near the upper end of the bevel so that the taper is longest on the sideof the tube which defines the lower end of the bevel and said taper progressively decreases in length around the tube in both directions from said side. 6. In a method of producing a shank as recited in claim 5 wherein said tube is made of carbon steel, the steps of heating the beveled lower end only of the tube to approximately 1600" F and quenching said lower end in oil to harden it.

References Cited UNITED STATES PATENTS 383,733 5/1888 Jenkins 223-102 X 1,932,516 10/1933 Gilleland 11280 1,937,257 11/1933 Van Dyke 1lZ80 2,051,915 8/1936 Sykes 148-39 X 2,636,460 4/1953 Seiderman 112-80 X 2,728,314 12/1955 Richards 112-222 X 2,786,788? 3/1957 Anderson 14839 X 2,804,413 8/1957 Essig et a1. 148-145 X 2,983,974 5/1961 Tebb et a1 148-145 X 3,089,442 5/1963 Short 112-79 PATRICK D. LAWSON, Primary Examiner.

I. R. BOLER, Assistant Examiner. 

1. A TUFTING NEEDLE COMPRISING A CYLINDRICAL SHANK PROVIDED WITH A CYLINDRICAL AXIAL YARN PASSAGEWAY, AND MEANS TO ADMIT AIR TO SAID PASSAGEWAY TO BLOW YARN THERETHROUGH, SAID SHANK BEING BEVELED AT ITS LOWER END, SAID PASSAGEWAY HAVING A YARN INLET OPENING AT ONE END AND AN INCLINED ELLIPTICAL YARN DISCHARGE OPENING AT ITS OTHER END DEFINED BY THE BEVEALED LOWER END OF SAID SHANK, SAID ELLIPTICAL YARN DISCHARGE OPENING BEING IN AXIAL ALIGNMENT WITH SAID PASSAGEWAY, SAID BEVELED LOWER END OF SAID SHANK BEING ARCUATE IN CROSS SECTION AND HAVING A TAPER EXTENDING CONVEXLY INWARDLY SUBSTANTIALLY AROUND ITS ENTIRE CIRCUMFERENCE, SAID TAPER MERGING SMOOTHLY WITH THE REMAINDER OF SAID SHANK AT A CIRCUMFERENTIAL LINE 